docs: resize docs bundler images and fix dimensions (#39824)

The dimensions must be of the non-2x image.

site/content/docs/5.3/getting-started/parcel.md

@@ -7,7 +7,7 @@ toc: true
 thumbnail: guides/bootstrap-parcel@2x.png
 ---
 
-<img class="mb-4 img-fluid rounded-3" srcset="/docs/{{< param docs_version >}}/assets/img/guides/bootstrap-parcel.png, /docs/{{< param docs_version >}}/assets/img/guides/bootstrap-parcel@2x.png 2x" src="/docs/{{< param docs_version >}}/assets/img/guides/bootstrap-parcel.png" width="2000" height="1000" alt="">
+<img class="d-block mx-auto mb-4 img-fluid rounded-3" srcset="/docs/{{< param docs_version >}}/assets/img/guides/bootstrap-parcel.png, /docs/{{< param docs_version >}}/assets/img/guides/bootstrap-parcel@2x.png 2x" src="/docs/{{< param docs_version >}}/assets/img/guides/bootstrap-parcel.png" width="800" height="400" alt="">
 
 {{< callout >}}
 **Want to skip to the end?** Download the source code and working demo for this guide from the [twbs/examples repository](https://github.com/twbs/examples/tree/main/parcel). You can also [open the example in StackBlitz](https://stackblitz.com/github/twbs/examples/tree/main/parcel?file=index.html) but not run it because Parcel isn't currently supported there.

site/content/docs/5.3/getting-started/vite.md

@@ -10,7 +10,7 @@ added:
   version: "5.2"
 ---
 
-<img class="mb-4 img-fluid rounded-3" srcset="/docs/{{< param docs_version >}}/assets/img/guides/bootstrap-vite.png, /docs/{{< param docs_version >}}/assets/img/guides/bootstrap-vite@2x.png 2x" src="/docs/{{< param docs_version >}}/assets/img/guides/bootstrap-vite.png" width="2000" height="1000" alt="">
+<img class="d-block mx-auto mb-4 img-fluid rounded-3" srcset="/docs/{{< param docs_version >}}/assets/img/guides/bootstrap-vite.png, /docs/{{< param docs_version >}}/assets/img/guides/bootstrap-vite@2x.png 2x" src="/docs/{{< param docs_version >}}/assets/img/guides/bootstrap-vite.png" width="800" height="400" alt="">
 
 {{< callout >}}
 **Want to skip to the end?** Download the source code and working demo for this guide from the [twbs/examples repository](https://github.com/twbs/examples/tree/main/vite). You can also [open the example in StackBlitz](https://stackblitz.com/github/twbs/examples/tree/main/vite?file=index.html) for live editing.

site/content/docs/5.3/getting-started/webpack.md

@@ -7,7 +7,7 @@ toc: true
 thumbnail: guides/bootstrap-webpack@2x.png
 ---
 
-<img class="mb-4 img-fluid rounded-3" srcset="/docs/{{< param docs_version >}}/assets/img/guides/bootstrap-webpack.png, /docs/{{< param docs_version >}}/assets/img/guides/bootstrap-webpack@2x.png 2x" src="/docs/{{< param docs_version >}}/assets/img/guides/bootstrap-webpack.png" width="2000" height="1000" alt="">
+<img class="d-block mx-auto mb-4 img-fluid rounded-3" srcset="/docs/{{< param docs_version >}}/assets/img/guides/bootstrap-webpack.png, /docs/{{< param docs_version >}}/assets/img/guides/bootstrap-webpack@2x.png 2x" src="/docs/{{< param docs_version >}}/assets/img/guides/bootstrap-webpack.png" width="800" height="400" alt="">
 
 {{< callout >}}
 **Want to skip to the end?** Download the source code and working demo for this guide from the [twbs/examples repository](https://github.com/twbs/examples/tree/main/webpack). You can also [open the example in StackBlitz](https://stackblitz.com/github/twbs/examples/tree/main/webpack?file=index.html) for live editing.